From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5)
Gecko/20050107 Firefox/1.0
Description of problem:
The upclick of a quick mouse click on a title bar in metacity doesn't
seem to be recognized. If you click quickly on a titlebar, it will
often be "stuck" to the mouse pointer and get dragged around until I
click again. This seems to be related to bug 109915. Going from
Update 3 to Update 4 fixed this on one system (2.4GHz Dell OptiPlex
GX260) but not another (2.8GHz Dell OptiPlex GX270). On the 2.8GHz
system, if I try to click as quickly as possible, about 1/4-1/2 the
clicks fail this way.
Version-Release number of selected component (if applicable):
metacity-2.4.55-7.12
How reproducible:
Always
Steps to Reproduce:
1. Run metacity, with or without GNOME.
2. Click very quickly on the title bar of any window.
Actual Results: The window gets dragged around until you click the
mouse again.
Expected Results: Should behave identically to a slower click.
Additional info:

Right, we have one or two other reports of continued problems with
this in U4 in the support issue tracker. Current theory seems to be
that there may also be a kernel or X issue. There could also be a
lingering metacity bug.